Getting client side crashes on different panel configurations. Crashes happens completly randomly when I try to operate elements.

java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
	at java.util.ArrayList$Itr.next(Unknown Source)
	at malte0811.industrialWires.controlpanel.PanelUtils.generateQuads(PanelUtils.java:83)
	at malte0811.industrialWires.client.panelmodel.PanelModel$AssembledBakedModel.func_188616_a(PanelModel.java:126)
	at malte0811.industrialWires.client.panelmodel.PanelModel.func_188616_a(PanelModel.java:74)
	at net.minecraftforge.client.model.pipeline.ForgeBlockModelRenderer.render(ForgeBlockModelRenderer.java:117)
	at net.minecraftforge.client.model.pipeline.ForgeBlockModelRenderer.func_187497_c(ForgeBlockModelRenderer.java:82)
	at net.minecraft.client.renderer.BlockModelRenderer.func_187493_a(BlockModelRenderer.java:47)
	at net.minecraft.client.renderer.BlockModelRenderer.func_178267_a(BlockModelRenderer.java:38)
	at net.minecraft.client.renderer.BlockRendererDispatcher.func_175018_a(BlockRendererDispatcher.java:80)
	at codechicken.lib.render.block.CCBlockRendererDispatcher.func_175018_a(CCBlockRendererDispatcher.java:60)
	at net.minecraft.client.renderer.chunk.RenderChunk.func_178581_b(RenderChunk.java:199)
	at net.minecraft.client.renderer.chunk.ChunkRenderWorker.func_178474_a(SourceFile:100)
	at net.minecraft.client.renderer.chunk.ChunkRenderWorker.run(SourceFile:43)
at java.lang.Thread.run(Unknown Source)

Full log https://gist.github.com/MrGraphic/ff3ce42d7a30ee348043c60c62622023
Also noticed slight fps drop when looking at panels in vertical position within operational range .

I'll look into this tomorrow, the first bug should be fixable. Regarding the second bug: "Operational range" means that you are close enough for the black outline/hitbox to show? And this only happens with panels placed against a wall?

ad. 1 no need to touch panel, happens also when indicators state changes.
ad. 2 yes, exactly that kind of "range". I have one panel on the ground and second one on the wall against panel connector. The first seems to be ok the second causes that drop.

Yeah, sorry for not showing this in the first place.

I have fixed the first issue. The second one I am not able to reproduce unless you are talking about a ridiculously small drop (~5 frames at 100 FPS (with VSync disabled and a much less powerful computer than yours)). I'll do some optimization regarding the hitboxes, I don't know whether it will help at all.

I have made some improvements, no idea whether they will help. The code related to hitbox rendering changed quite a bit when I implemented tilted panels, that might have helped too.

Thanks for a fix.
About that fps drop, no idea what is going on ( labels ? ) - both has been rearranged few times:

Yep, it is the labels. I completely forgot to add equals/hashCode methods for them and never noticed it since they are "boring" and I don't use them in dev... I'll get a new build out tomorrow to fix this. The build I published today won't do anything about the lag since I looked in the completely wrong place.